Devices used for altering the spacing of articles in a conveying system are well known in the art. The repositioning of discrete articles in a conveying system can be utilized in the manufacture of disposable diapers, feminine hygiene products, incontinence control garments, and the like. In such a system, discrete abutting segments of an absorbent material cut from a continuously moving web of material can be repositioned to form a spaced apart array upon a continuously moving web of substrate material.
Articles, such as disposable diapers, are generally made with a liquid-impervious backing sheet upon which absorbent pads are positioned and covered by a liquid-pervious top sheet. The resulting composite material is then generally formed into a discrete article. In many cases, it may be desirable to place discrete absorbent pads in spaced apart locations on the liquid-impervious back sheet (or onto a liquid-pervious front sheet) that can serve as the substrate upon which the absorbent pads are placed. The discrete absorbent pads are usually cut from a continuously moving web of absorbent material or material formed in place, yielding pads in an abutting relationship on a conveyor system. Consequently, an apparatus and process for placing the discrete absorbent pads onto the substrate web with a selected spacing between adjacent webs can become necessary. Conversely, it may also be desired to place individual articles of an array of spaced apart articles into a continuous abutting array. In any regard, the spacing between adjacent articles on a moving conveyor system may be required to change from one distance to another.
However, current systems generally utilize a cam track in order to move a carriage having a plurality of suction cups mounted thereto. The cam track moves the carriage radially outward during rotation to enable a suction cup to grip an object at an unloading station. The object is then moved outwardly toward the output device. In order to change the spacing of the placed articles, a new cam track having the new path directions must be installed. Such devices are shown in Jackson, U.S. Pat. No. 3,834,522.
Other methods utilized for changing the spacing between a plurality of articles include the use of paired rolls operating at different peripheral speeds in order to separate individual articles passing therethrough. Such a system is disclosed in Banks, U.S. Pat. No. 3,494,001, and Buhayar, U.S. Pat. No. 3,827,545.
Other methods of adjusting the spacing of articles comprise a rotating element having a plurality of equally spaced cranks, each crank being provided with a suction housing for holding and releasing an article. Each crank is connected to the rotating device by a link that causes the crank to oscillate at a rate that matches the velocity of the inlet conveyor as the conveyor rotates. Such an apparatus is discussed in Seragnoli, U.S. Pat. No. 4,506,779. Yet still another method of altering the spacing in a plurality of conveyed articles incorporates the use of a rotating drum having fixed and radially extending arms. The radially extended arms can engage a dispensed object, such as a diaper, as the arm rotates about its own axis. Such an apparatus is disclosed in Campbell, U.S. Pat. No. 4,394,898.
Accordingly, it would be desirable to provide a device that is capable of adjusting the spacing between articles of a moving array of discrete articles. Further, it would be desirable to provide an apparatus that is continually adjustable and capable of higher production speeds without the need to stop production in order to provide changes to the space changing system.